One example of a lock ring that locks a disc brake rotor to a bicycle hub is described in U.S. Pat. No. 6,371,252 to Kanehisa, which is incorporated herein by reference. The bicycle hub includes a hub axle, which is fixed to a bicycle frame in a non-rotatable manner, and a hub shell, which is rotatably supported by the hub axle. One end of the hub shell includes a tubular mount, which extends outward in the axial direction to enter a center bore of a disc brake rotor, and a flange, which extends outward in the radial direction to contact the perimeter of the center bore in the disc brake rotor. The tubular mount includes a female-threaded inner circumferential surface.
The lock ring includes a central tube, which has a smaller diameter than the tubular mount of the hub shell, and a flange, which extends outward in the radial direction from the central tube. The central tube of the lock ring includes a male-threaded outer cylindrical surface. Each of the central tube and the flange is a rigid body.
A method for using the lock ring will now be described. First, the tubular mount of the hub shell is inserted into the center bore of the disc brake rotor. Then, the male-threaded portion of the central tube of the lock ring is engaged with the female-threaded portion of the tubular mount of the hub shell. The lock ring is rotated relative to the tubular mount so that the flange of the lock ring and the flange of the hub shell rigidly sandwich the disc brake rotor. In this manner, the lock ring fixedly locks the disc brake rotor to the bicycle hub.